Help me fix my A/C

[EquatorHeat00]

Car A/C doesn't work, and the fans never come on even sitting in traffic at a stop light. Car was checked out diagnosis no signal from pcm for a/c relay. Mad Z28 sent me another pcm which has been installed over a week ago. A/C still doesn't work, and fans never come on just like before. (Obviously not the problem.)
Anybody know what the problem is here, or a way I can fix it for free? (Send me pictures if possible.)

[DJ Taso]

Sounds like you have a freeon leak. Buy a charge kit at any auto store, start the car up and have the AC running. As soon as the freeon hits the line, the fans should start up.

That was my case..

[Trash man]

bring it to a shop have then put it under a vac. and convert it ro R134a. they will put a dye in it and they use a black light to fix the leak. ur low on freeon(which u cant buy without a license) and ur fans arent gettin the signal to turn on cuz the low pressure switch is telling the computer - nuh uh

[Jeff_in_Atl]

bring it to a shop have then put it under a vac. and convert it ro R134a. they will put a dye in it and they use a black light to fix the leak. ur low on freeon(which u cant buy without a license) and ur fans arent gettin the signal to turn on cuz the low pressure switch is telling the computer - nuh uh

94s are already R134.

[Trash man]

some are some arent, the grand prix we had at the college was a 94 with R12 but it was a early production 94

[Jeff_in_Atl]

some are some arent, the grand prix we had at the college was a 94 with R12 but it was a early production 94

He has a Camaro. It is R134.

[EquatorHeat00]

Car uses r 134 a and I was told it didnt need any refrigerant. I think the fans not coming on is why its not cold. When I tested the pressure of the a/c line at home it was very high.

[Jeff_in_Atl]

The low pressure side will get really high if the fans don't come on. The fan should come on whenever the A/C clutch on the compressor kicks in.

[EquatorHeat00]

So how do I get my fans to turn on, and is this the problem?

[BrdWAtti2d]

The secondary fan is triggered by the A/C head pressure. No pressure, no fan. So even with the compressor running if it's not coming up to pressure the fan won't kick in. I don't remember the exact pressure threshold, sorry. The primary fan isn't triggered by the A/C but triggered on temp. So if the primary fan isn't kicking in and the car is up to temp there is another issue not related to the A/C.

[Craig 94 TA GT]

Did you ever end up trying to scan your DTC codes for an A/C failure code (again this will not throw an SES light as it's a hidden code that forces the PCM not to kick the A/C on).

[TraceZ]

He says there is no signal from the PCM for the AC Relay.

That would do it right there. I know with freescan, when I scan my 94 I can look and see if the AC is on in the software. I turn the dash knob to AC and the light on my laptop turns on to reflect the change.

Get a wire diagram and find which wire goes from the PCM to the AC relay. Test the relay and test the wire to the PCM. To test the wire, unplug the connector on both ends and probe it with an ohms meter.

Scan your car with freescan. If the AC light comes on you know the dash knob is working. If the AC light does not come on, troubleshoot the HVAC controls on the dash.

[Jeff_in_Atl]

The secondary fan is triggered by the A/C head pressure. No pressure, no fan. So even with the compressor running if it's not coming up to pressure the fan won't kick in. I don't remember the exact pressure threshold, sorry. The primary fan isn't triggered by the A/C but triggered on temp. So if the primary fan isn't kicking in and the car is up to temp there is another issue not related to the A/C.

I'm not sure how a GM works, (that is not how a Ford works) if that is true then if it is low on freon then the compressor won't kick in. It may just need freon. This would also explain why there is no power to the A/C relay.